Air preheater for locomotives



June 10, 1930. F. LJUNGSTROM 1,752,445

AmLRaEHEATER FOR LOCOMOTIVES Filed March 19, 1926 IN V5 TOR F re drik lljwlysfr'm J mat 61M 4.; A TTORNE V Patented June 10, 1930 uurreo STATES FREDRIK LJUNGSTRGM, OF LIDINGO-BBEVIK, Sit/EDEN AIR PREHEATER FOB LOCOMOTIVES Application filed March 19, 1926. Serial No. 95,984.

This application is to be considered as relatlng backto my copendmg applications Sefirial No. 460,600, filed April 11, 1921, and Serial No. 579,541, filed Aug. 3, 1922.

The invention relates to steam generating plants and has for its purpose to provide an air preheating combustion and steam generating unit of a high degree of eiiiciency.

The invention will be readily understood upon reference to the following description taken in connection with the accompanying drawings which show several embodiments of my invention.

In the accompanying drawings,

Figure 1 is a view showing my invention applied to a locomotive;

Fig. 2 is a section on the line 2-2 of Figure 1; and i r Fig. 3 is a detail of the packing means employed.

In the figures, 39 designates generally a locomotive with a cab 40, a main barrel 89, a fire box 41, a grate 42 and an ash pit 43. From the furnace 41 fire tubes 44 extend for wardly to the front tube sheet 45 in-front of: which is situated the smoke box 46 which is substantially an extension of main barrel 89. Below the smoke box 46 isan air chamber 47 having an opening 48 in the same at its forward end for admission of air. Situated partly in chamber 47 and partly in smoke box 46 and extending through a hole in floor 88 which separates smoke box 46 from air chamber 47 is the movable part of an air preheater 4 which comprises a rotary cylindrical framework as in the previous case. The preheater is shown more in detail in Fig. 2 and comprises anouter cylindrical drunr 68 and a central shaft core 49 between which extend radial walls 50 dividing the same into sector shaped compartments which contain regenerative material composed of alternate flat and corrugated plates, 80 and 81 respectively. The plates are so arranged as to form axially extending passages through the rotor 4 and are co-extensive in length with the axial length of the drum 68. The arrangement is such that the open ends of the cylindrical drum 68, the ends of the core 49 and the ends of the metal plates constituting the regenerative material all he in two parallel planes. The rotor 4 rotates about shaft 51 which is supported in bearings 52 and 53. The shaft driven by means ot a turbine 54 connected to shaft 51 by a reduction gear 55. 56 designates a hood sru-roumling rotor 4 to prevent leakage to a substantial degree.

Around the outside of the rotor and between the outer cylindrical drum of the rotor and hood 56 and the outer walls oi chamber 47 are placed strips 57 consisting of thin metal attached to one of the relative members and bearing against the other.

The lloor of smoke box 46 extends close up to the rotor 4 on either side and attached to the floor and bearing against the rotor are strips 58, 59 shown in detail in l? 3. These ti rhtcningor packing strips may l 3 attached to the floor of the smoke box in any suitable way. In the example shown, this is done by bolts 60 extending through concentric holes in the floor and the strips and brace barsol placed outside of the strips. The tightening strips of Fig. 3 are of such nature as to conrpletely close off each passage as it enters from one channel to the other. In this case it is not necessary that the strips be as far apart as the walls forming the sector shaped chambers but since the regenerative mate rial extends to the planes determined by the i open ends of the outer cylindrical drum of the rotor, the strips need only be so far apart as to cut off the widest channel between plates or between corrugations of the same plate.

In the operation of the locomotive, coal is tired ongrate42 and the products of combustion pass through tubes 44 and thence throughthc passages 19 in the rotor 4 which lie above the leakage preventing strips 59. The products of combustion heat the metal of the preheater surrounding these passages which are in the upper portion above strips 59 to a high degree and the metal of the prehcater thus absorbs and accumulates the heat of the products of comlilustion. After pass ing through these passages 19 the products of combustion pass out through stack 82. Steam supplied to turbine 54 by means of pipe 83, flow through which is controlled by valve 84 operable from the cab through levers 85 and 86. Supply of steam to turbine 54 causes rotation of rotor 4 so that the passages 19 which were in the upper portion of the rotor are moved to a position below the floor of the smoke box 46 so that they are in communication with chamber 47. Fresh air supplied through opening 48 now passes through chamber 47 through the passages 19 which are in open communication with chamber 47 and thence through channel 87 connected with chamber 47 behind rotor 4 and extending under the main barrel 89 to ash pit 43, to the under side of grate 42, and thence through the fuel. The heat accumulated in the metal is given off to the fresh air passing from chamber 47 through the lower passages 19 and the fresh air is thus heated to a very high degree furnishing highly pr heated air for combustion.

By having a continuous uniform rotation f'the rotor 4 and having the same divlded into a multitude of the channels each of which is temporarily isolated in its change of communication with respect to the path of fresh air 4787 and the path of the hot products of combustion through smoke box 46 and by adequately separating the fresh air from the hot products of combustion and still further by conducting preheated fresh air below the grate and through the fire a uniform quality of air is supplied for combustion at all times whereby high combustion efiiciency is made possible.

Obviously instead of having floor 88 in a. plane, as shown it may be curved to the contour of the main barrel. Many other changes in construction will be obvious within the scope of the invention.

The'strips 58 and associated parts form the subject matter of a separate copending application, Serial No. 71,871, filed on November 27, 1925..

It is to be noted that the space under hood 56 to the rear of frame-work 4 may be considered as the supply channel for hot products of combustion; the forward portion of smoke-box 46 may be considered as a discharge channel for hot products of combustion; the forward part of chamber 47 which is directly connected to opening 48 may be considered as the supply channel for air; and the rear portion of chamber 47 directly connected with channel 87 may be considered as the discharge channel for heated air.

By the arrangement shown and described wherein channel 87 extends under the main barrel 89, the whole portion of the main barrel can be used for generation of steam since all the fire tubes are thus made available for conveyance of the products of combustion.

Having thus described my invention what I claim is:

1. A locomotive comprising a furnace, an ash pit, a smoke-box, a chamber beneath said smoke-box, a floor separating said chamand air passageways.

her and said smoke-box, said floor having an opening in the same, a frame-work posited partly in said smoke-box and partly in said chamber and extending through said opening, means to rotate said frame-work, said framework containing a plurality of axially placed metal members arranged to form a plurality of passages through the frame-work, separating members between the edges of said opening and said frame-work, means to supply air to said chamber and a channel connecting said chamber with said ash pit.

2. A locomotive comprising a furnace, an ash pit, a main barrel, a smoke-box formed substantially as an extension of said main barrel, flues extending through said barrel connecting the furnace with the smoke-box, an air chamber beneath said smoke-box and beneath said main barrel, a floor separating said chamber and said smoke-box, said floor having an opening in the same, a frame-work posited partly in said smoke-box and partly in said chamber and extending through said opening, means to rotate said frame-work, a plurality of axially placed metal members arranged in said framework to form a plurality of passages through the frame-work, members attached to said floor and extending between the edges of said opening and said framework, said members being adapted to isolate each of said passages successively as the passages change communication between the smoke-box and theair chamber, means to supply air to said air chamber on the foreside of said frame-work and a channel con-- forward to the smoke-box and all air supplied passes through said channel.

3. A locomotive comprising a boiler, a

smoke stack, a combustion chamber, a preheater of the regenerative type having separated passages therethrough, a gas passageway conducting flue gases from said combustion chamber to said smoke stack, an air passageway conducting combustion air to said combustion chamber, partition means between said preheater and combustion chamber completely separating said air and gas passageways and preventing communication therebetween, and means for including said preheater passages successively in said gas 4. A locomotive comprising a boiler, a smoke stack, a combustion chamber, a preheater of the regenerative type having sepa rated passages therethrough, a gas passageway conducting flue gases from said combustion chamber to said smoke stack, an air passageway conductingcombustion air to said combustion chamber, partition means between said preheater and combustion chamber completely separating said air and gas passageways and preventing communication therebetween, and means for rotating said preheater to successively include said preheater passages in said gas and air passageways.

5. A locomotive comprising a boiler, a smoke stack, a combustion chamber, a preheater of the regenerative type having separated passages therethrough, a gas passageway conducting flue gases from said combus' tion chamber to said smoke stack, and an air passageway conducting combustion air to said combustion chamber, said passageways being longitudinally disposed in said locomotive, partition means between said preheater and combustion chamber completely separating said air and gas passageways and preventing communication therebetween, and means for including said preheater passages successively in said gas and air passageways.

6. A locomotive comprising a boiler, a smoke stack, a combustion chamber, a prelieater of the regenerative type having separated passages therethrough, a gas passageway conducting flue gases from said combustion chamber to said smoke stack, and an air passageway conducting combustion air to said combustion chamber, said passageways being longitudinally disposed in said locomotive, partition means between said preheater and combustion chamber completely separating said air and gas passageways and preventing communication therebetween, and means for rotating said preheater to successively include said preheater passages in said gas and air passageways.

in testimony whereof I hereunto afiix my signature.

FREDRIK LJUNGSTROM. 

